UNI EN 1998-6 : 2005

1 GENERAL
  1.1 SCOPE
  1.2 REFERENCES
  1.3 ASSUMPTIONS
  1.4 DISTINCTION BETWEEN PRINCIPLES AND APPLICATION
        RULES
  1.5 TERMS AND DEFINITIONS
        1.5.1 Special terms used in EN 1998-6
  1.6 SYMBOLS
        1.6.1 General
        1.6.2 Further symbols used in EN 1998-6
  1.7 S.I. UNITS
2 PERFORMANCE REQUIREMENTS AND COMPLIANCE CRITERIA
  2.1 FUNDAMENTAL REQUIREMENTS
  2.2 COMPLIANCE CRITERIA
        2.2.1 Foundation
        2.2.2 Ultimate limit state
        2.2.3 Damage limitation state
3 SEISMIC ACTION
  3.1 DEFINITION OF THE SEISMIC INPUT
  3.2 ELASTIC RESPONSE SPECTRUM
  3.3 DESIGN RESPONSE SPECTRUM
  3.4 TIME-HISTORY REPRESENTATION
  3.5 LONG PERIOD COMPONENTS OF THE MOTION AT A POINT
  3.6 GROUND MOTION COMPONENTS
4 DESIGN OF EARTHQUAKE RESISTANT TOWERS, MASTS AND
  CHIMNEYS
  4.1 IMPORTANCE CLASSES AND IMPORTANCE FACTORS
  4.2 MODELLING RULES AND ASSUMPTIONS
        4.2.1 Number of degrees of freedom
        4.2.2 Masses
        4.2.3 Stiffness
        4.2.4 Damping
        4.2.5 Soil-structure interaction
  4.3 METHODS OF ANALYSIS
        4.3.1 Applicable methods
        4.3.2 Lateral force method
              4.3.2.1 General
              4.3.2.2 Seismic forces
        4.3.3 Modal response spectrum analysis
              4.3.3.1 General
              4.3.3.2 Number of modes
              4.3.3.3 Combination of modes
  4.4 COMBINATIONS OF THE EFFECTS OF THE COMPONENTS OF
       THE SEISMIC ACTION
  4.5 COMBINATIONS OF THE SEISMIC ACTION WITH OTHER
       ACTIONS
  4.6 DISPLACEMENTS
  4.7 SAFETY VERIFICATIONS
       4.7.1 Ultimate limit state
       4.7.2 Resistance condition of the structural
             elements
       4.7.3 Second order effects
       4.7.4 Resistance of connections
       4.7.5 Stability
       4.7.6 Ductility and energy dissipation
             condition
       4.7.7 Foundations
       4.7.8 Guys and fittings
  4.8 THERMAL EFFECTS
  4.9 DAMAGE LIMITATION STATE
  4.10 BEHAVIOUR FACTOR
       4.10.1 General
       4.10.2 Values of modification factor k[r]
5 SPECIFIC RULES FOR REINFORCED CONCRETE CHIMNEYS
  5.1 SCOPE
  5.2 DESIGN FOR DISSIPATIVE BEHAVIOUR
  5.3 DETAILING OF THE REINFORCEMENT
       5.3.1 Minimum reinforcement (vertical and
             horizontal)
       5.3.2 Minimum reinforcement around openings
  5.4 SPECIAL RULES FOR ANALYSIS AND DESIGN
  5.5 DAMAGE LIMITATION STATE
6 SPECIAL RULES FOR STEEL CHIMNEYS
  6.1 DESIGN FOR DISSIPATIVE BEHAVIOUR
  6.2 MATERIALS
       6.2.1 General
       6.2.2 Mechanical properties for structural
             carbon steels
       6.2.3 Mechanical properties of stainless steels
       6.2.4 Connections
  6.3 DAMAGE LIMITATION STATE
  6.4 ULTIMATE LIMIT STATE
7 SPECIAL RULES FOR STEEL TOWERS
  7.1 SCOPE
  7.2 DESIGN FOR DISSIPATIVE BEHAVIOUR
  7.3 MATERIALS
  7.4 DESIGN OF TOWERS WITH CONCENTRIC BRACINGS
  7.5 SPECIAL RULES FOR THE DESIGN OF ELECTRICAL
       TRANSMISSION TOWERS
  7.6 DAMAGE LIMITATION STATE
  7.7 OTHER SPECIAL DESIGN RULES
8 SPECIAL RULES FOR GUYED MASTS
  8.1 SCOPE
  8.2 SPECIAL ANALYSIS AND DESIGN REQUIREMENTS
  8.3 MATERIALS
  8.4 DAMAGE LIMITATION STATE

Describes the requirements, criteria, and rules for the design of tall slender structures: towers, including bell-towers, intake towers, radio and TV-towers, masts, chimneys (including free-standing industrial chimneys) and lighthouses.